Cut chicken into 1 inch strips; set aside. Combine yogurt, lemon juice, chili powder, garlic powder and ground cumin in a medium bow; stir well. Add chicken strips, and toss to coat. Cover and marinate in refrigerator for 8 hours, stirring occasionally.
Preheat over to 350° F.
Remove chicken from marinade, discarding marinade. Dredge chicken strips in tortilla crumbs. Place chicken on a baking sheet coated with cooking oil spray. Bake at 350° F. for 35 minutes or until lightly browned an crisp. Serve immediately.